<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="../vue.js"></script>
</head>

<body>
  <div id="app">
    <button @click = "isHot = !isHot">点击切换天气</button>
    <p>今天天气真{{isHot? "热" : "冷"}}啊</p>
    <img :src="src" alt="">
  </div>
  <script>
    Vue.config.productionTip = false;
    
    const vm = new Vue({
      el: "#app",
      data() {
        return {
          isHot: true,
          src: "./re.webp"
        }
      },
      //监听配置
      watch:{
        //监听isHot的改变渲染不同的图片

        //没有深度监听 和立即监听 可以简写
          isHot(value){
              this.src = value? "./re.webp" : "./leng.gif"
          }
      }
      
    })
  </script>
</body>

</html>